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A project of Volunteers in Asia New Himalayan Water Wheels by A. Bachmann and Akkal Man Nakarmi Published by: UNICEF P-0, Box 1187 Kathmandu NEPAL Available from: Sam? as above Reproduced by permission. Reproduction of this microfiche document in any form is subject to the same restrictions as those of the original document. d . M E I TE ANGREAS BACHMANN AND AKKAb MAN NAKARMI SAHAYOGI PRESS KATHMANDU Fublished by: Sahayogi Press Tripureshwar Kathmandu Phone: 11'489 First Edition: November 1983 The opinions expressed and arguments employed in this publication are the responsibility of the authors and do not necessarily represent - those of any organization. Copyright is reserved by the authors, but permission is hereby granted for the reproduction of any part, text or drawing, for non-pLofit publication; however the whole booklet, or any major portion, should not he reproduced wk!:hout permission. Anyone making use of material presented herein is requested to aclcnow- ledge the source and submit to the authors a copy of the excerpt. Printed in Nepal at Sahayoqi Press CONTENTS Acknowledgement Foreword Introduction -7 9 11 Development of Modern Water Mills and Mini Turbines - 13 Contentional Mini Hydra Turhines The Multi-Purpose Power-Unit 15 16 Alternative Designs for Rural People - Wooden Cross Flow Turbine - "Metal Pelton", Low-Head - Wooden Water Wheel. - New Nepali Water Mills 18 19 19 20 21 Conclusion 23 Photographs -__i_ - Traditional Water Power Utilization --- 27 - Multi-Purpose Power-Unit 36 - New Nepali Water Mills 40 - Applications 49 Technical Drawinqs - Traditional Horizontal Water Mill--- 53 - New Nepali Water Mills (Two Samples)- 54 - Multi-Purpose Power-Unit 55 - Construction 56 - 67 Construction Materials _ -_, .._ 68 List of Appliance; 71 Table af Comparison 72 Technical Data 74 List of Development Works _ 75 List of Modern Hydro Development 76 List of Nanufacturers 78 References 80 List of Literature 82 ACKNOWILDGEMENT The improvement of traditional mills is a story in itself. Some of the first trials were considered, for example, by late Rev. B.R. Saubolle. We are also grateful to many people, especially to the farmers for their interest and cooperation, Jtirgen Steiger (W.-Germany), Corneille Jest (France), Fritz Maurer (Bhutan) and organizations: the Agricultural Develop- ment Bank/Nepal, UNICEF, and others for their generous,steady support. A very good incentive for continuing the search for alternative means of utilizing mini hydro power was provided by UNESCO and the German Nepal Help Association. UNESCO agreed to assist the implementation of a mini hydro project propo- sal, and the German Nepal Help Association is assisting pilot mill installations. We believe that such contributions are very useful for many people. We are also thankful to Mr. Gerry Neville for his valuable assistance to improve this booklet. We are grateful for this assistance in our search for alternative means of utilizing small scale hydro power. We believe that such efforts can have far reaching impact provided that the knowledge and experiences gained are widely disseminated, so that it reaches even the remote corners in developing countries, for we believe that it is people in these situations who stand in greatest need of help to make their lives easier. Andreas Eachmann Akkal Man Nakarmi Water-powered prayer wheel in the Himalaya. 9 FOREWORD Water power is a recognized natural resource in Nepal. There are thousands of traditional water mills still in operation. Interesting enough, the same types of water mills were widespread in medieval Europe and played an important roie in the earliest stages of industrializa- tion. Over the past, much effort has been experienced to improve the efficiency with which water power is used and modern turbines have been developed for farmers, or on large scale, water power for todays' industrial needs. On the other hand, until recent times, little effort has been made to improve the smallest scale water wheels which, even today, are the most widely dispersed means of using hydro power. This may have been due to uncer- tainity about the usefulness of such improvements. Until recent times efforts at improving mini hydro power systems have been hindered by lack of engineering expertise, and also by a scarcity of information on the subject. The basic idea in developing alternative hydro power systems is to find ways to keep these small power sources useful and within the reach of rural people. Yet it is obvious that improvements such faster grinding and the capacity to run additional machines, are often needed. The designs presented in this paper show certain achieve- ments, gained tlhrough mainly a practical approach. It is hoped that quite a bit sroves useful for further design developments, and also for the actual construction of many more small scale power systems in the Himalyan moun- tains, and wherever else there is potential for such 10 power systems. It is not claimed however, that these first results are the final word on the subject. This recognises that much more work is necessary. It is hoped however, that this booklet will encourage further effort for the improvement of mini hydro power systems, and with stimulates the dissemination of information on these efforts. 11 INTRODUCTION The utilization of Mater power for the grinding of wheat with horizontal water mills is an old tradition in Nepal. These mills, made locally in many parts of the Himalaya still serve a good part of the population, especially in the more remote areas. It is estimated there are between 25,000 and 40,000 still operating in Nepal alone, but reliable data are not available. The people in the hills depend upon agriculture for their survival. They live scattered all over the country and are largely self-reliant. They do not yet have easy access to kerosene for lighting, and it will take quite some time before many of these villagers will have the chance to be connected to any central power supply. Until recently the traditional technology of horizontal water wheels for agriculture processing was quite ade- quate for the needs of rural people. Now, however, with the inc:ease in population the traditional patterns are changing. These days the limitations of the traditional mills -their low productivity and their capacity to only grind grain- are being more keenly felt. People often have to walk 10x hours to reach the nearest water mill. They have to wait for hours until their turn comes, then wait again 2:~ have their grain ground. After that, is the long walk back home. At home, other work will be waiting: oil expelling, rice hulling, food preparation, etc. Their situation is becoming more critical: increasing population places greater strain upon traditional techno- logies; more and more time must be spent collecting fire- Wood, family members have to wait longer and longer at 12 traditional mill sites. This demand for higher productivity has led some entrepreneurs to the conclusion that diesel motors, which are more productive, can therefore be more profitable. However, for these engines fuel must be imported, thus establishing dependency upon foreign supr'iers. Precious foreign exchange is drained away from the country to pay for these imports. 13 DEVfiLOPMENT OF MODERN WATER MILLS AND MINI TURBINES Kew water powered devices were introduced some two or three decades ago. Firstly the undershot wheel was developed, made of wood, and copied by various mill sites. With these larger water wheels more power could be made available for agricultural procesus such as: grinding, oil expelling, rice hulling, rice flattening. These wheels were quite heavy, require much material for their construction and needed replacement every six to eight years or so. They also had a limited power production of approx. three to eight horse power. Almost twenty years ago another type of turbine was developed at BYS: the propeller turbine. A few were made, but the idea did not really catch on and the production ceased. A few individuals or small workshops developed their own designs, for example Overshot and Undershot Water Wheels, made of metal, etc. As they were a private initiative 1/ they did not become well known.- In 1973/1974 a new attempt was launched, again at BYS. At first a cross flow turbine was developed and then in- 21 stalled at Baglung -. Soon after the Butwal Technical Institute adopted the same type of turbine and other 3/ manufacturers followed -. Nowadays approx. 150 of khese are functioning all over the country. They are used for agro processing through belt-driven systems, and in ranges of 10 to 1.5 h.p. Some efforts were also made with existing traditional water mills. There were trials with simple improvements on the lifting/lowering device of the grinding stone; 14 a power take-off derived from the upper stone; adding a small dynamo for lighting purposes, etc. However, the ideas did not spread and this possibly for several reasons; for example, the trials were not successful enough, and specialists and organizations active in the field of hydro power did not, at that time, support the idea of such mini hydro power devices. Then, in 1979 a Seminar-Workshop on Mini Hydro Electric Generation was held in Kathmandu. On this occasion Jean Gimpel brought several models with him. One of them demonstrated the principle of a "Bulgarian Water Mill" (which is quite similar to the present Nepalese design, but with some improved features on it. His idea was to use models as tools for technology transfer to rural areas. Though the improvement of traditional water mills was not really a new one he was successful in motivating people in Kathmandu to think over the existing, traditional water mills.?' Then in Godavari two sites were selected for pilot plant installations: 1) One version was made of wood for grinding purposes, which could also run a bicycle dynamo.5' 2) At the other site was installed an early version of the Multi-Purpose Power-Unit (MPPU). This was made of metal and could grind, drive ,a rice huller, an oil expeller and a car dynamo. y:gr Significant attention was given to these prototype c10/;11/ At the Workshop-Seminar of Renewable Energy Resources in Kathmandu, 1981, the questionnaire filled in by the 15 participants showed clearly the interest and priority 12/ given to it.- CONVENTIONAL MINI HYDRO TURBINES Traditional Water Mills no longer alwalrs meet the daily needs of rural people. The growing population da,,nds more from machines than ever before. The traditional water mills have many advantages: the people are able to make these mills in their own surroundings.'Wood and stones are the materials mainly used. A few iron parts are added: the bottom pieces, the upper part of the ver- tical axle, and the top key - which turns the upper stone. The hammers used to redress the stones are made of steel also. As people can use materials from their rural surroundings the cost is almost nil. Work can be done anywhere in the fields: the grinding stones cut from a larger rock; the open chute cut from a nea.rby tree. Repairs are no real difficulty; local skills can maintain these machines. Modern Metal Turbines: Developments have originated mainly from larger workshops. These workshops have the necessary machines for welding, turning, etc., whatever is required for precision and durable workmanship. The products reach a quite high standard and enable greater production in a relatively short time: identical turbines can be made in an assembly line. Modern technology, often imported from the Western Herni- sphere, can be much more productive. The constructions need often to be redesigned to suit local conditions. Almost all of the materials are imported (steel, bearings,